如何加入选择与自己？

Question

1. 与自己连接表是没问题的。但我需要加入一个创建的选择。第一个想法：使用临时表，但我只能打开一次。这是真的吗？

2. MySQL是否足够智能，只计算一次具有相同术语的子选择？ 例如：

   join (select * from asdf where term) as one
   join (select * from asdf where term) as two
   ...
   join (select * from asdf where term) as ten
   

通常如何解决？

Answer 1

您可以多次加入临时表

    select * into #temp from asdf where term
    ...
    join #temp as one
    join #temp as two
    ...
    join #temp as ten